Primary Aldosteronism Clinical Presentation

Updated: Mar 02, 2018
  • Author: Gabriel I Uwaifo, MD; Chief Editor: Romesh Khardori, MD, PhD, FACP  more...
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Presentation

History

The clinical presentation of primary aldosteronism is not distinctive, and the correct diagnosis requires a high index of suspicion on the part of the physician. The common clinical scenarios in which the possibility of primary aldosteronism should be considered include the following:

  • Patients with spontaneous or unprovoked hypokalemia, especially if the patient is also hypertensive [15]

  • Patients who develop severe and/or persistent hypokalemia in the setting of low to moderate doses of potassium-wasting diuretics

  • Patients with treatment-refractory/-resistant hypertension (HTN)

Patients with severe hypokalemia report fatigue, muscle weakness, cramping, headaches, and palpitations. They can also have polydipsia and polyuria from hypokalemia-induced nephrogenic diabetes insipidus. Long-standing HTN may lead to cardiac, retinal, renal, and neurologic problems, with all the associated symptoms and signs.

In a study comparing the cardiac effects of primary versus secondary aldosteronism, Cesari et al determined that while both types of aldosteronism were frequently characterized by left ventricular hypertrophy and diastolic dysfunction, only primary aldosteronism was associated with evident subclinical systolic dysfunction. Moreover, patients with primary aldosteronism had lower heart rates and higher blood pressure and vascular resistance values than did those with the secondary condition, while plasma renin activity was lower in primary than in secondary aldosteronism (0.56 vs 15.00 ng/mL/h, respectively). [16]

Familial primary aldosteronism

The 2 major familial varieties of primary aldosteronism are glucocorticoid-remediable aldosteronism (GRA; type 1 familial primary aldosteronism) and a non–glucocorticoid-remediable type (type 2 familial primary aldosteronism).

The recognition of GRA is particularly important because of its implications for patients who are hypertensive and whose family members are apparently unaffected. HTN, strokes, and other significant cardiovascular events are described in young persons with this syndrome.

Although the syndrome is uncommon, heightened levels of suspicion are essential for the diagnosis. Fewer than 200 well-validated cases exist in the literature. All patients with GRA should be treated medically with glucocorticoids and without surgery.

Although uncommon, GRA may be more prevalent than was previously presumed. A significant subgroup of patients with the milder normokalemic variety of this syndrome is probably incorrectly presumed to have essential HTN. [10]

A family history of HTN (particularly with a young age of onset), HTN in children, low-renin HTN, and presumed IAH are the typical situations in which this diagnosis should be considered.

The third type of familial PA, due to mutations in the KCNJ5 potassium channel-coding gene, is considered to be exceedingly rare, but can also lead to HTN and hypokalemia at a very early age.

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Physical Examination

Patients with primary aldosteronism do not present with distinctive clinical findings, and a high index of suspicion based on the patient's history is vital in making the diagnosis. The findings could include the following:

  • Hypertension (HTN) - This condition almost invariably occurs, although a few rare cases of primary aldosteronism unassociated with HTN have been described in the literature.

  • Weakness

  • Abdominal distention

  • Ileus from hypokalemia

  • Findings related to complications of HTN - These include cardiac failure, hemiparesis due to stroke, carotid bruits, abdominal bruits, proteinuria, renal insufficiency, hypertensive encephalopathy (confusion, headache, seizures, changes in the level of consciousness), and hypertensive retinal changes

It is important to note that primary aldosteronism in and of itself is typically not associated with edema, despite the volume-expanded state associated with it. The lack of edema results from spontaneous natriuresis and diuresis (called the "aldosterone escape") that occurs in patients with primary aldosteronism and that appears to be mediated by atrial natriuretic peptide (ANP). [17, 18] Of note, this effect is probably based on the activation of the apical ATP/UTP/P2Y2 receptor system (at the connecting tubule/collecting duct level), leading to increased presentation of sodium, which, in turn, induces closure of the epithelial sodium channel (ENaC), with resultant decrease in sodium reabsorption (ie, enhanced natriuresis). [19] Hence, the finding of significant edema in patients who are presumed to have aldosteronism suggests either that a wrong diagnosis has been made or that associated complications, such as renal or cardiac failure, are present.

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